New Seal-Fast Liqui-Flash polyurethane roofing sealant from Mule-Hide Products Co. Inc. seals complex details quickly and permanently. The one-component, 100% solids, non-shrink, polyurethane sealant can be used in typical and difficult-to-access applications, including flashings, skylights, pitch pockets (filling and sealing), inlaid gutters, air conditioners, brick ties, roof vents, penetrations, ductwork, roof hatches, chimneys and seams. It is compatible with a wide range of substrates, including metal, polyurethane foam, aged smooth asphalt, aged modified bitumen, aged PVC and aged EPDM.